| Abbreviation | Definition |
|---|---|
| ISIR | Institute for Screen Industries Research |
| ISIR | Institute for Systematic Investing Research |
| ISIR | Institute of Scientific and Industrial Research |
| ISIR | Institute Of Standards Industrial Research |
| ISIS | Institute of Science in Society |
| ISIT | Iron and Steel Institute of Thailand |
| ISK | Institution of Surveyors of Kenya |
| ISL | Institute of Salt Lakes |
| ISLA | Institute for Scholarship in the Liberal Arts |
| ISLG | Institute for State and Local Governance |
| ISLS | Institute for Spanish Language Studies |
| ISLT | Institute for Science Law and Technology |
| ISM | Institute For Statistical Manipulation |
| ISM | Institute of Sales Management |
| ISM | Institute of Statistical Math |
| ISM | Institute of Statistical Mathematics |
| ISMC | Institute for Sustainable Malaria Control |
| ISMD | Institute for the Study of Mongolian Dinosaurs |
| ISME | Institute for Science and Math Education |
| ISME | Institute of Sheet Metal Engineering |